Feed roll driving means for duplicating machines



April 3, 1956 c. A. LEVIN 2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14, 1951 3Sheets-Sheet l April 3, 1956 c. A. LEVIN 2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14, 1951 3Sheets-Sheet 2 INVEN TOR. Carl ,2. z ez/Z'rz April 3, 1956 c. A. LEVIN2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14. 1951 3Sheets-Sheet 3 INVENTOR. ("GI 1.7% lee/27a FEED ROLL DRIVING MEANS FORDUPLICATING MACHINES Carl A. Levin, Park Ridge,

porated, Chicago,

lll., assignor to Ditto, incor- Ill., a corporation of West Virginia.

This invention relates to duplicating machines of the wet process type,and in particular, {to improved means for driving the feeding andmoistening rolls.

Duplicating machines of this type are provided with a drum, a pressureroll in contact therewith, and a pair of feed rolls disposed in front ofthe bite of the drum and pressure roll. These feed rolls serve thecombined func tion of feeding a copy sheet into engagement with the drumand pressure roll, of moistening one surface of the copy sheet as it isbeing fed, and of positioning the copy sheet. To accomplish thepositioning and feeding functions, the feed rolls are intermittentlydriven; the copy is fed into the bite of the feed rolls when the latterare stationary. Then when the feed rolls start to rotate, the leadingedge of the copy sheet is grasped by the feed rolls and fed intoengagement with the drum and pressure roll. A suitable master sheet iscarried on the drum. The timing of the dwell period of the feed rolls issuch that proper registration of the copy sheet and the master sheet isobtained.

Two types of intermittent driving mechanisms have heretofore been used.In one type, the'upper feed roll is positively driven from the drum ordrum shaft by mutilated gearing through a major portion of eachrevolution of the drum. The disadvantage of this mutilated gearing isthe fact that the feed rolls are accelerated up to maximum speed veryrapidly. This results in shock to the mechanism and noisy operation;since the feed rolls are brought up to maximum speed in about one toothlength.

The other type of intermittent driving mechanism involves the use of acam driven oscillating sector which serves to positively drive the upperfeed roll only through a peripheral distance which is sulficient toadvance the copy sheet into a position in-which the leading edge thereofis grasped by the bite of the drum and feed roll. This mechanismprovides lower acceleration, resulting in smoother and quieteroperation. Furthermore, it provides better registration since there isless likelihood of initial slippage between the copy sheet and the feedrolls. After United States Patent the copy sheet has been engaged by thedrum, the copy sheet drags the feed rolls, and to permit this, anoverrunning clutchjis interposed between the intermittent drivingmechanismand the upper feed roll.

In addition to the above advantages which relate to feed rollacceleration, this sector type of mechanism avoids the accumulation ofmoisture in the absorbent lower feed roll since the feed rolls come to astop almost immediately after trailing the edge of the copy sheet aspassed between thefeed rolls. 'In the mutilated gearing type ofmechanism, when a' short copy sheet is fed, the continued rotatibn ofthe upper feedroll transfers a substantial amount of solvenfto the lowerfeed roll which moisture is later transferred to the undersurface ofsubsequent copy sheets 'audthenceto the pressure roll which may laterresult in offsetting.

It has been found that the oscillating sector type of intermittentdriving mechanism is not satisfactory for motor driven machines. This isfor the reason that it "ice is very dilficult to obtain an exact balancebetween the moisture applied to the feed roll and the moisture removedfrom the feed roll by means of the copy sheet. After a motor drivenmachine has been run continuously for a substantial period of time,'if'the balance is not correct, an over-supply of moisture will causeslippage of the copy sheet with respect to the feed rolls, with theresult that the copy sheet will not drag the feed rolls, and theremaining portion of the copy sheet will not be moistened. This slippagebecomes particularly aggravated when the 'copy sheet is in the form ofnarrow sheets, strips, tickets and the like.

It is an object of the present invention to provide an improved feedroll driving mechanism which combines the advantages of both types ofdriving mechanism pointed out above, and eliminates the disadvantages ofeach.

Another object is to provide an improved feed roll driving mechanismwhich positively drives the feed roll through the greater part of eachrevolution of the drum.

Still another object is to provide in combination with an intermittentfeed roll driving mechanism of the oscillating sector type, an auxiliarydriving mechanism which will serve to extend the period during which thefeed rolls are positively driven so that slippage may be prevented.

A further object is to provide auxiliary feed roll driving mechanismwhich can be readily disengaged when it is desired not to use the same.

A still further object of this invention is to provide improvedmoistening, feeding and positioning means for a wet process duplicatingmachine which is operative on narrow copy sheets as well as on copysheets of standard width.

With reference now to the drawings in which like reference numeralsdesignate like parts:

Fig. l is a side elevation of a fragmentary duplicating machineembodying my invention;

Fig. 2 is a vertical sectional view of the machine of Fig. 1 showing therelationship of the various elements referred to above;

Fig. 3 is an elevation of the auxiliary driving mechanism shown in Fig.1, taken along line 3-3 of Fig. 1;

Fig. 4 is a detail section taken along line 4-4 of Fig. 1;

Fig. 5 is an elevation, partially in section of the opposite side of themachine from that shown in Fig. 1, showing the oscillating sector typeof driving mechanism;

Fig. 6 is a vertical section taken along line 6-6 of Fig. 5; and

Fig. 7 is a detailed sectional view taken along line 77 of Fig. 6,showing the overrunning clutch.

In the drawings, which illustrate a preferred embodiment of thisinvention, the reference numerals 10 and 11 designate the right and leftside frames, respectively, of a duplicating machine. A drum shaft 12 issuitably journaled in the side frames and carries a drum 13. Suitablemeans, not shown herein, are provided for driving the drum and drumshaft. The drum is provided with the usual means, not shown herein, forsecuring a master sheet to its surface.

A pressure roll 14, as shown in Fig. 2, is disposed below the drum forpressure engagement therewith. The pressure roll is carried in a bracket15 which is pivoted on a shaft 16 so that it may be resiliently urgedagainst the drum.

Disposed in front of the bite of the drum and pressure roll is a pair offeed rolls comprising upper feed roll 17 and lower feed roll 18. Theupper feed roll 17 may be formed from neoprene or the like, and thelower feed roll may be formed from a sponge rubber or other absorbentmaterial. As shown in Figs. 3 and 6 a tubular portion of a 3 shaft 19provided for the upper feed roll 17, in which shaft are disposed rightand left extensions 20 and 21, respectively. The shaft extensions arejournaled in the side frames by means of ball bearing units 22 and 23,respectively.

The lower feed roll 13 is mounted in pivoted brackets 24 and 25,respectively, so that it may be resiliently urged into engagement withthe upper feed roll 17.

As shown in Fig. 2 the duplicating machine is provided with a moistener26 which includes a spray tube 27 disposed above the upper feed roll 17,a wiper 23 which en gages the upper feed roll, and mounting means 29 forpartially enclosing and supporting the wiper. The wiper may be made offelt. During each revolution of the drum, a measured amount of solventis sprayed onto the upper feed roll by the spray tube, and this solventis uniformly distributed over the surface of the feed roll by the wiper.

A feeding throat 30 is disposed immediately in front of the bite of thefeed rolls and is aligned with the usual feed tray so that a copy sheetmay be directed into the bite of the feed rolls when they arestationary. Subsequent rotation of said feed rolls will cause theleading edge of the copy sheet to be fed into the bite of the drum andpressure roll, and the timing is such that proper registration with themaster sheet will be obtained.

Two driving mechanisms are provided so that the feed rolls may beintermittently driven, the primary driving mechanism being disposed atthe left side of the machine, and being shown in Figs. 5 and 6 andtheauxiliary driving means being disposed at the right side of themachine and being shown in Figs. 1 and 3. The primary driving mechanismincludes an oscillating sector 31 which ispivotally mounted on the leftside frame '11 as shown in Fig. 5 by means of a pivot 32. The sector 31is provided with teeth 33 which mesh with a pinion 34 concentricallymounted with respect to shaft extension 21. A unidirec tional drivingconnection is provided with the pinion 34 and the shaft extension bymeans of an overrunning clutch 35, shown in Figs. 6 and 7. The sector 31is driven by a groove earn 36, mounted on the drum shaft 12 whichengages a follower 37 in the form of a roller, which is carried on thesector 31. The groove cam is adjustably mounted with respect to the drumshaft by means of screws 38 and slots 39, the screws taking into asuitable flange or hub member on the drum shaft. Thus, the angularposition of the groove cam with respect to the drum can be shifted inorder to vary the time at which the rotation of the feed rolls iscommenced, thereby regulating the registration. The groove cam isprovided with a rise portion 40 and with a drop portion 41. In theposition of the parts as shown in Fig. 5, the feed rolls have justcommenced their rotation. Subsequent rotation of the drum and the cam inthe direction indicated by the arrow will cause the sector to swing tothe right with a gradually accelerated motion, thereby causing theleading edge of a copy sheet to be fed into the bite of the drum andpressure roll. The cam rise is so designed that the peripheral speed ofthe feed rolls at the time that the leading edge of the copy sheet isengaged by the bite of the drum and pressure roll will be equal to theperipheral speed of the drum. The provision of the cam and sectorarrangement permits a gradual acceleration of the feed rolls up to thisspeed, thereby permitting more positive engagement of the leading edgeof the copy sheet and avoiding the shock and noise inherent in othertypes of mechanism.

Due to the provision of the overrunning clutch 35, the return stroke ofthe sector does not affect the continued and unidirectional rotation ofthe feed rolls.

The auxiliary driving mechanism, as shown in Figs. 1 and 3, includes asector 45, a friction wheel 46 driven. thereby, and suitable gearingbetween the friction wheel and the upper feed roll 17. The sector may besuitably secured to the drum shaft or the drum as by set screws 47.

The friction wheel 46 is preferably formed of rubber to permit properfrictional engagement with the driving edge of the sector 45, whichmaybe formed of metal or other hard material.

The friction wheel 46 forms a part of an idler assembly 48, shown inFig. 4, which is rotatably mounted on a shoulder stud 49. The latterextends outwardly from a support plate 50 to which it is suitablysecured. The idler assembly includes a bushing 51 having a flange 52. Apinion 53 is riveted to the flange 52. The friction wheel 46 is confinedbetween the flange 52 and a clamping disk 54 which is threaded onto theend of the bushing 51 so as to securely hold the friction wheel46againstrslippage on the bushing. Thus, all of the elements of the idlerassembly 48 rotate as 'a unit on the shoulder stud 49. The idlerassembly is spaced from the shoulder of the shoulder stud 49 by asuitable felt lubricating washer 55, and it issecured in position on thestud by means of a washer 56 and a retaining ring 57 which snaps into anannular groove formed at the end of stud 49.

The idler pinion 53 meshes with a pinion 58 which is suitably secured tothe shaft extension 20 of the upper feed roll. Thus, the upper feed rollmay be intermittently rotated by the sector 45. The support plate 50 isadjustably mounted on side frame 10 by means of an eccentric bolt 60 anda screw 61 which passes through a slot 62 in the support plate and takesinto the side frame 10. The eccentric bolt 60 is provided with aneccentric shoulder 63 which engages the circular edge of a cut-outportion 64 of the support plate, as shown vin Fig. l. The head of theeccentric bolt confines one end of the support plate against the frame10. The support plate is provided with a circular opening so that it maybe fitted over the bearing unit.22 to provide-a pivoted mounting. Thus,by loosening the nut 65 and the screw 61, the angular disposition of thesupportplate can be regulated to a precise degree merely by changing theangular position of the eccentric shoulder 63 of bolt 60. This permitsregulation of the frictional engagement of the friction wheel with thesector, and it also permits the friction wheel to be disengaged entirelyfrom the sector when operation of the auxiliary driving means is notdesired.

It will be observed that the corner edges of the sector 45 are rounded,as indicated by the reference numerals 66, so as to .minimize the shockof engagement and disengagement.

The operation of the invention has been pointed out in connection withthe description of the various parts of the duplicating machine. Tosummarize, a copy sheet which has been positioned at the bite of thefeed rolls when they are stationary, will be advanced by the feed rollswith a gradually accelerated motion so that the leading edge of the copysheet will be fed into the bite of the printing couple. At this time,the speed of the feed rolls and of the copy sheet is equal to the drumspeed. The rotation of the feed rolls during this period is controlledby the primary driving means. If it .is desired to use the secondarydriving means, the support plate 50 is rocked and secured in a positionso that the friction wheel 46 is engaged by sector 45. The length of thesector is such that the feed rolls will be positively driven throughouta peripheral distance which corresponds to the standard length of copysheet which is used in straight line duplicating.

The primary driving means is preferably operative to drive positivelythe copy sheet at the drum speed for a short time after the leading edgehas been engaged bythe printing couple, so as to provide for anoverlapping of the operative positions of the cycles of the two drivingmechanisms. Thus, by regulating the extent of the overlap, by adjustingthe angular position of the sector, by means of the set screws 47, thetotal time during which the feed rolls are positively driven may beregulated to correspond with the length of the copy sheet to beduplicated-upon. However, where the length of the copy sheets variessubstantially from the standard length, a different size sector may besubstituted for sector 45. In the alternative, two or more overlappingor telescoping sectors may be employed to permitsubstantial variationwithout the necessity of substituting ditferent sectors.

For a series of shot runs on copy sheets of standard width, such as maybe encountered during so-called systerns operation as contrasted withstraight run duplicating, the problem of slippage may not occur sinceevaporation during periods of inactivity will prevent over-moistening.In such a situation, the secondary driving means can be renderedinoperative by shifting the support plate 50 and the friction wheel 46out of engagement with the sector 45.

The present invention is of utility when mutilated gearing is used forthe primary driving means, provided that the mutilated drive gear is ofcomparatively short length. In such situations, the secondary drivingmeans positively drivestthe feed rolls when slippage is likely to occur;at other times, the secondary driving means may be reudered inoperativeso that the feed rolls will come to rest even though a short copy sheetis used.

I claim:

1. In a duplicating machine having a rotatable cooperating pressure rollproviding a printing couple, the combination of a pair of intermittentlydriven feed rolls disposed in front of the bite of said printing couple,primary driving means'for positively drivingsaid feed rolls through aperipheral distance corresponding to the distance between the bite ofsaid feed rolls and the bite of said printing couple and actuated by therotation of the drum, said primary driving means embodying meansproviding a positive driving connection between said drum and one ofsaid feed rolls to initiate the rotation of said feed roll as said drumpasses through a predetermined angular position, and auxiliary means fordriving said feed roll after a copy sheet has been fed by said feedrolls into engagement with the bite of said printing couple, saidauxiliary means embodying means providing a frictional drivingconnection between said drum and said feed roll.

2. In a duplicating machine of the class described having a drum, a feedroll, primary and auxiliary driving means for the feed roll, saidauxiliary driving means comprising a friction sector rotating with thedrum and a rotatable member driven thereby to provide a frictionaldriving connection, together with a further driving connection betweensaid rotatable member and said feed roll, the combination of a mountingplate on which said rotatable member and said driving connection aremounted, and means for mounting said mounting plate for pivoted movementabout the axis of said feed roll, whereby the angular position of saidmounting plate may be shifted to throw said rotatable member into andout of engagement with said sector.

3. Auxiliary driving means for a duplicating machine having a frame, adrum, a feed roll rotatably mounted in said frame, and primary drivingmeans for said feed roll, comprising a friction sector rotating withsaid drum, a rotatable member positioned to be engaged and to befrictionally driven thereby, a driving connection between said rotatablemember and said feed roll, a plate pivotally mounted on said frame forangular adjustment about the axis of said feed roll, and means forsecuring said plate to said frame including a bolt mounted on said frameand having a head engaging a surface of said plate for confining theplate against said frame, said rotatable member and said drivingconnection being rotatably mounted on said plate, and an eccentricshoulder on said bolt bearing against a portion of said plate forregulating the angular position of said plate and the engagement betweensaid to tatable member and said sector.

4. In a duplicating machine having a drum and a cooperating pressureroll providing a printing couple, the combination of a pair ofintermittently driven feed rolls disposed in front of the bite of saidprinting couple, primary driving means for positively driving said feedrolls through a peripheral distance corresponding to the distancebetween the bite of said feed rolls and the bite of said printing couplesaid primary driving means comprising an 0scillating sector, a piniondriven thereby, an overrunning clutch disposed between said pinion andone of said feed rollsaio provide unidirectional rotation thereof andcam means rotating with said drum to cause oscillation of said sector,said cam means having a gradually rising rise portion for imparting anaccelerated motion to said sector and said feed rolls throughout asubstantial portion of the time during which said feed rolls are sodriven whereby a copy sheet-positioned in the bite of said feed rollswhen stationary may be fed with a gradually accelerated motion into thebite of said printing couple at a speed substantially equal to theperipheral speed of said drum, and auxiliary driving means comprising afriction sector mounted on said drum, a friction wheel positioned to beengaged thereby, and means establishing a driving connection betweensaid friction wheel and said feed roll, said sector being constructedand arranged so as to drive said feed roll at a peripheral speedsubstantially equal to the peripheral speed of said drum after said copysheet has been engaged in the bite of said printing couple andthroughout a period of time subsequent thereto which period terminatesprior to the time that said primary driving means is again operative.

5. In a. duplicating machine having a drum and a cooperating pressureroll providing a printing couple, the combination of a pair ofintermittently driven feed rolls disposed in front of the bite of saidprinting couple, a moistener for said feed rolls including a wipermember engaging one of said feed rolls, primary intermittent positivedrive means for positively driving said feed rolls through a peripheraldistance corresponding to the distance between the bite of said feedrolls and the bite of said printing couple, auxiliary intermittent drivemeans for said feed rolls after rotation thereof through said peripheraldistance and throughout a period of time subsequent thereto which periodterminates prior to the time said primary means is again operative inorder to extend that portion of the cycle of operation during which saidfeed roll is driven, and overrunning clutch means associated with saidfeed roll to permit unidirectional rotation of said feed roll at alltimes, said auxiliary intermittent driving means including a frictionsector, and means for adjustably mounting said sector on said drum sothat said portion of said cycle of operation can be regulated toaccommodate sheets of different length.

6. In a duplicating machine having a drum and a coopcrating pressureroll providing a printing couple, the combination of a pair ofintermittently driven feed rolls disposed in front of the bite of saidprinting couple, primary driving means for positively driving said feedrolls through a peripheral distance corresponding to the distancebetween the bite of said feed rolls and the bite of said printingcouple, said primary driving means comprising an oscillating toothedsector, a pinion driven thereby, an overrunning clutch disposed betweensaid pinion and said feed rolls to provide unidirectional intermittentrotation of said feed rolls, a groove cam rotating with said drum forcausing oscillation of said sector, and auxiliary drive means comprisinga friction sector rotating with the drum of said duplicating machine, afriction roller intermittently driven thereby, and a driving connectiondisposed between said friction roller and said feed rolls, the angularrelationship between said grooved cam and said friction sector being anoffset relationship so that said auxiliary drive means will impartrotation to said feed rolls after said feed rolls have been rotatedthrough said peripheral distance by said primary driving means.

7. In a duplicating machine having a drum and drum shaft and a pressureroll cooperating with said drum to provide a printing couple, thecombination of a pair of feed rolls disposed in front of the bite of theprinting coupie, said feed rolls including a combined moistening andfeeding roll, primary driving means therefor adapted to impartintermittent rotation thereto to advance successive copy sheets into thebite of said printing couple, overrunning clutch means disposedbetween-said primary driving meansand said feed roll to permitunidirectional rotation of said feed roll at times when said primarydriving means is inoperative, and auxiliary driving means forestablishing an intermittent driving connection betWeensaid-drum shaftand said moistening and feeding roll, the operative portion of the cycleof said auxiliary driving means commencing after said moistening andfeeding roll has been rotated by said primary driving means through aperipheral distance corresponding .to the distance between the bite ofsaid feed .rolls and the bite of said printing couple so that a givencopy sheet will be engaged in the bite of-said printing couple when'saidoperative portion commences, and terminating after said primary drivingmeans has become inoperative so that said moistening and feeding rollwill be driven throughout a period greater than that provided by eitherof said driving means.

8. Driving mechanism as claimed in claim 6 including means foradjustably mounting said friction sector on said drum.

9. In a duplicating machine having a rotatable drum and a cooperatingpressure roll providing a printing conple, the combination of a pair ofintermittently driven feed rolls disposed in front of the bite of saidprinting couple, primary driving means for positively driving said feedrolls and actuated by the rotation of the drum to initiate the rotationof said feed roll as said drum passes through a predetermined angularposition and to accelerate the same up to drum speed, said primary meansembodying 8 a geared connection to provide an initial driving action,and embodying a first member rotating with said drum,

and auxiliary means providing a frictional drive 'forsaid' feedrolhsaidauxiliary means comprising asecondmem-w ber rotatingwith'saiddrum and provided with .a frictional driving =surface, arotatable drivenelement positioned to be fr'ictionally engaged by saidsecond member, and Ea driving :connection between said second member andsaid driven element, said second member being in the form of a sectorangularly arranged so that it will not engage said driven element untilafter sai-dfeed rolls have been rotatedby said primary means through aperipheral distance corresponding ito the distance between the bite ofsaid feed rolls and the bite of said printing couple, one

of saidmembers being vadjustably mounted withrespect to said drum, saidauxiliary means providing a frictional driving connection so that theoperation of the same is not dependent .upon any given .increment ofadjustment, and said primary driving means providing apositivedrivingconnection so that the relative speeds of said drum andfeed roll are not affected by inertia.

References Cited in the file of this patent UNITED STATES PATENTS1,247,732 Shelton Nov. '27, 1917 2,185,682 Pittman Jan. 2, 19402,192,908 Harrold et a1. Mar. 12, 1940 2,268,045 Marchev Dec. 30, 19412,271,954 Rockhill Feb. 3, 1942 2,299,974 Grobecker Oct. 27, 19422,588,917 Geib Mar. 11, 1952 2,594,179 'Keil Apr. 22, 1952

